In place of a soldering method, the present invention provides an electronic components mounting structure in which in connection between electronic components and conductors, insulation between the conductors are performed efficiently, connection portions between the electronic components and the conductors are aligned so as to be welded easily, and the conductors are assembled in a stacked state so as to increase the mounting density.
In the background art, electrical connection of electronic components was performed in a manner so that the electronic components were mounted on a substrate and connected to wiring patterns formed on the substrate. In such a configuration, since the wiring patterns were formed with copper foil and current capacity was small, the configuration could not be used in a large current circuit. In such a case, it was required that, as shown in FIG. 12, a copper plate good in electrical conductivity and called a bus bar 111 was projected from an electrical circuit portion 110, and a top end of a lead terminal 101 of an electronic component 100 was passed through a hole 112 formed in the busbar 111 to make connection between the lead terminal 101 and the busbar 111 by soldering.
In a location with severe environment for use of automobiles or the like, reliability was lowered due to deterioration of soldering or the like, for example, cracks generated in a soldering portion, because of temperature change, vibrations or the like.
Further, from the viewpoint of the problem of environmental contamination in recent years so as to make the soldering free from lead, use of conventional solder is limited, and in order to promote recycling, it has become necessary to reconsider the solder connection.
Conventionally, connection to such busbars was performed by soldering. However, since copper was good in heat conduction, workability of soldering was poor. At the same time, such soldering was often made manually. These facts were primary factors causing increase in cost.
Accordingly, the present invention, therefore, provides an electronic components mounting structure for performing connection between lead of electronic components and metal conductors having large current capacity, in place of a soldering method, in which insulation between the metal conductors are performed efficiently, connection portions between the electronic components and the metal conductors are aligned so as to be subjected to connection work by welding or the like efficiently, and the metal conductors are assembled in a stacked state so as to improve assembling property and increase the mounting density.
The present invention will be described briefly with reference to FIG. 1. In FIG. 1, the reference numeral 1 represents a box casing; 2, cover casing; 3-1 and 3-2, first protrusion portions; 4-1 and 4-2, second protrusion portions; 5-1 to 5-3, third protrusion portions; 6 to 13, conductors; and 21 to 24, electronic components.
The first protrusion portions 3-1 and 3-2, the second protrusion portions 4-1 and 4-2, the third protrusion portions 5-1, 5-2 and 5-3 are formed on the box casing 1. Further, a first protrusion portion 2-1 for conductor holding is formed on the cover casing 2.
First, the first protrusion portions 3-1 and 3-2 of the box casing 1 are inserted into hole portions 6-1 and 6-2 of the conductor 6, the third protrusion portion 5-2 is inserted into a hole portion 7-1 of the conductor 7, the second protrusion portion 4-2 is inserted into a hole portion 7-2, the third protrusion portion 5-3 is inserted into a hole portion 7-3, the second protrusion portion 4-1 is inserted into a hole portion 9-1 of the conductor 9, and the third protrusion portion 5-1 is inserted into a hole portion 9-2, so that these conductors 6,7 and 9 are arranged to be insulated from each other and located in the lowest portion of the box casing 1.
Next, the second protrusion portions 4-1 and 4-2 are arranged so that the second protrusion portion 4-1 is inserted into a hole portion 8-1 of the conductor 8, and the second protrusion portion 4-2 is inserted into a hole portion 8-2. At this time, as shown in the left lower portion of FIG. 1, each of the hole portions 8-1 and 8-2 in the conductor 8 is formed in such a size that the conductor 8 is supported on a step portion 4A, and an insulation configuration is formed so that the conductor 8 does not come into contact with the conductors 6, 7 and 9 arranged in the lowest portion of the box casing 1.
Then, the second protrusion portion 4-1 is inserted into a hole portion 10-1 of the conductor 10. At this time, as shown in the left lower portion in FIG. 1, the hole portion 10-1 of the conductor 10 is formed in such a size that the conductor 10 is supported on a step portion 4B, and an insulation configuration is formed so that the conductor 10 does not come into contact with the conductors 9 and 8 arranged on lower and middle steps of the box casing 1.
Similarly, the first protrusion portion 3-1 is inserted into a hole portion 11-1 of the conductor 11. At this time, as shown in the right lower portion in FIG. 1, the hole portion 11-1 of the conductor 11 is formed in such a size that the conductor 11 is supported on a step portion 3B, and an insulation configuration is formed so that the conductor 11 does not come into contact with the conductors 6 and 8 arranged on lower and middle steps of the box casing 1. The conductors 12 and 13 are subjected to similar insulation arrangement.
The conductors are held by a first protrusion portion 2-1 formed to project from the cover casing 2 for conductor holding, as shown by way of example in the left lower and right lower portions of FIG. 1. Of course, other conductors are also pressed by protrusion portions not shown.
When the box casing 1 is covered with the cover casing 2, external connection terminals a to h, which are provided in the box casing 1 to be formed on the respective conductors for connection, project from external connection terminal inserting holes A to H so as to be electrically connected with an external circuit.
Lead terminals r, 1, t, . . . of the electronic components 21 . . . are formed on the respective conductors and aligned so as to be opposite to connection portions R, L, T . . . located outside the box casing 1 and the cover casing 2, so that welding can be performed easily.
The problem can be achieved by the present invention in the following items (1)xcx9c(3).
(1) An electronic components mounting structure which has a plurality of electronic components (21, 22, 23, 24) having lead terminals respectively, and conductors (6, 7, 8, 9, 10, 11, 12, 13) having connection portions to be connected to the lead terminals of the electronic components, wherein the lead terminals of the electronic components (21, 22, 23, 24) are aligned with the connection portions of the conductors and the lead terminals and the connection portions are welded with each other.
(2) An electronic components mounting structure as stated in the item (1) which has a plurality of electronic components (21, 22, 23, 24) having lead terminals respectively, and conductors (6, 7, 8, 9, 10, 11, 12, 13) connected to the lead terminals, wherein the conductors are arranged in a resin casing so as to be insulated from each other, and wherein external connection terminals of the conductors which are not connected to the electronic components are collected on one and the same surface of the resin casing.
(3) In an electronic components mounting structure as stated in the item (1), protrusion portions (3-1, 3-2, 4-1, 4-2, 5-1, 5-2, 5-3) are provided at a part of the resin casing so that the conductors (6, 7, 8, 9, 10, 11, 12, 13) to be connected to the electronic components (21, 22, 23, 24) are assembled in a stacked state in the protrusion portions to thereby improve assembling density and workability of the electronic components.
In accordance with the above-mentioned items, the following operations and effects can be obtained.
(1) Since the lead terminals of the electronic components are aligned with the connection portions of the conductors, the lead terminals and the connection portions of the conductors are welded with each other sequentially and easily by using a welding device, so that the connection work by welding can be carried out very efficiently.
(2) Since the external connection terminals of the conductors which are not connected to the electronic components are collected on one and the same surface of the resin casing, a connector can be connected easily to the external connection terminals when a connection portion such as a control board is disposed on the resin casing.
(3) Since the protrusion portions are provided at a part of the resin casing so that the conductors are assembled in a stacked state in the protrusion portions, assembling density and workability of the electronic components are improved.